that the orb of night is 81
times less heavy than our planet. There is nearly as much difference in
weight between the Earth and the Moon as between an orange and a grape.

* * * * *

Not content with weighing the planets of our system, astronomers have
investigated the weight of the stars. How have they been enabled to
ascertain the quantity of matter which constitutes these distant
Suns--incandescent globes of fire scattered in the depths of space?

They have resorted to the same method, and it is by the study of the
attractive influence of a sun upon some other contiguous neighboring
star, that the weight of a few of these has been calculated.

Of course this method can only be applied to those double stars of which
the distance is known.

It has been discovered that some of the tiny stars that we can hardly
see twinkling in the depths of the azure sky are enormous suns, larger
and heavier than our own, and millions of times more voluminous than the
Earth.

Our planet is only a grain of dust floating in the immensity of Heaven.
Yet this atom of infinity is the cradle of an immense creation
incessantly renewed, and perpetually transformed by the accumulated
centuries.

And what diversity exists in this army of worlds and suns, whose regular
harmonious march obeys a mute order....

But we have as yet said nothing about weight on the surface of the
worlds, and I see signs of impatience in my readers, for after so much
simple if unpoetical demonstration, they will certainly ask me for the
explanation that will prove to them that a kilogram transported to
Jupiter or Mars would weigh more or less than here.

Give me your attention five minutes longer, and I will restore your
faith in the astronomers.

It must not be supposed that objects at the surface of a world like
Jupiter, 310 times heavier than our own, weigh 310 times more. That
would be a serious error. In that case we should have to assume that a
kilogram transported to the surface of the Sun would there weigh 324,000
times more, or 324,000 kilograms. That would be correct if these orbs
were of the same dimensions as the Earth. But to speak, for instance,
only of the divine Sun, we know that he is 108 times larger than our
little planet.

Now, weight at the surface of a celestial body depends not only on its
mass, but also on its diameter.

In order to know the weight of any body upon the surface of the Sun, we
must ar